The invention relates to the composition comprising nanoparticle ginkgo biloba extract with the effect of brain function activation.
Ginkgo biloba extract has been conventionally obtained as powder after ginkgo biloba extracted with alcohol is adsorbed to porous resin to be concentrated and dried at high heat. The extract of ginkgo biloba is recognized for comprising the active ingredient with pharmacological effects: restoring the weakened vessels by direct action on vessel wall and restoring flexibility of hardened vessels, decreasing peripheral resistance by thinning the thick blood, enhancing immune function or inhibiting platelet activator. It has been used extensively, especially in France or Germany, as a drug for improvement of cerebral blood flow and metabolism. Ginkgo extract is also consumed as food as can be seen from some health food claiming comprising it in the market. Ginkgo extract, additionally, in skin preparation is recognized for normalizing and promoting peripheral circulation under the skin and achieving significant cosmetic effects. As for useful components in ginkgo biloba, their effects are revealing; anti-stress ulcer effect of salicylic acid derivative (patent literature 1), blood pressure-lowering effect of flavone glycoside, specific to ginkgo biloba (nonpatent literature 1) or inhibitory effect of gikgolides on platelet activator has been reported.
However on the other hand, ginkgo biloba component contains ginkgolic acid which is a kind of hydrophobic, salicylic acid derivative causing allergy or polyphenolic compound (proanthocyanidin) with water solubility and browning reaction. They must be removed when ginkgo biloba extract is used in drugs, foods or cosmetic materials. The procedures of obtaining the extract with active ingredient of ginkgo biloba are generally acknowledged; they all employ the highly toxic, low-boiling and difficult-to-remove solvent so that the extract may not contain salicylic acid derivative or polyphenolic compound but may have high active ingredient of flavone glycoside and terpene lactones. The extraction procedure avoiding using highly toxic organic solvent is disclosed, which utilizes purification of the hydroalcoholic extract with porous nonpolar resin (patent literature 2 and 3). While this procedure provides the way to obtain ginkgo biloba extract only with the ethanol appropriate to food manufacturing, use of porous nonpolar resin has the drawback of requiring additional energy to its regeneration and solvent recovery.                Patent Literature 1: Kokai (unexamined patent publication) No. 63-215629 (1988-215629)        Patent Literature 2: Kokai (unexamined patent publication) No. 3-275629 (1991-275629)        Patent Literature 3: Kokai (unexamined patent publication) No. 4-182434 (1992-182434)        Nonpatent Literature 1: Proceedings of the 107th Annual Meeting of the Pharmaceutical Society of Japan, (in Japanese) p. 345        